Developing tank



Oct. 14, 1941. c. MACE 2,259,259

DEVELOPING TANK Filed Nov. 20, 1959 2 Sheets-Sheet l 'ul Z? "I 22 2/ nw- IIIII INVENTOR CHARLES MACE.

BY f i ATTORNEY Oct. 14, 1941. c. MACE DEVELOPING TANK 2 Sheets-Sheet 2 Filed Nov. 20, 1959 YINVENTOR CHARMS MACE.

B MORNEY Patented Oct. 14, 1941 UNITED STATES PATENT OFFICE DEVELOPING TANK Charles Mace, Denver, 0010.

Application November 20, 1939, Serial No. 305,239

Claims.

This invention relates to a photographic device for the development of negatives.

It is well-known among professional photographers that the most perfect results in developing are still obtained by the old tray method wherein the negatives are placed in developing trays in which both the negatives and the solution can be kept constantly agitated to create constant movement of the developer over the emulsion in all directions and to obtain uniform development. This is not possible in the usual developing tank even though an agitator may be employed since the solution tends to travel in definite paths over portions of the negative causing uneven development thereof.

The principal object of this invention is to provide a developing device which will simulate tray development, that is, in which the contact between solution and the emulsion will have all; of the characteristics that is had in the usual tray developer so that an absolutely uniform surface development is obtained over all of the negatives in the tank.

Other objects of the invention are to provide a developer of this nature which will be light proof during the development operation; which will not only create agitation in the solution but will also create movement in the negatives; in which all agitation and movements will be adjustable; in which the negatives can be quickly and easily inserted or removed without spilling or scattering the developing solution; which will be equally applicable for both fiat films or plates and rolled films; and in which all parts can be instantly disassembled and reassembled for washing and cleaning.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efliciency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views of the drawings and throughout the description.

In the drawings:

Fig. 1 is a longitudinal section through the improved developer.

Fig. 2 is a cross section thereof, taken on the line 2 2, Fig. 1.

Fig. 3 is a detail view illustrating the roll film attachment.

Fig. 4 is a plan view of the developer with the cover removed.

Fig. 5 is a cross section, taken on the line 5-5, Fig. 1.

Fig. 6 is a detail section illustrating the motor mounting.

The entire apparatus is enclosed in a water proof outer box In which can be hermetically sealed by means of a lid II. The lid is formed with an internal rubber gasket I2, preferably but not necessarily, extending over its entire under surface. The gasket I2 is clamped in place against the lid by means of a flanged inner lid I3 which is secured to the outer lid by means of a clamp screw I4. The lid may be clamped in place on the box ID by means of a turnable, resilient clamping bar I5 which extends through, and is secured in, a rotatable pivot member I B on the lid.

The extremities of the bar I5 are received in hooked ears I! extending upwardly from the sides of the box I0. To place the bar I5 in position, it is necessary to spring the extremities thereof downwardly so that the natural resiliency of the bar will clamp the lid in place and force the gasket I2 against the upper edge of the box I 0, thereby sealing the latter. The box is made additionally light proof by a flange on the lid I3 which extends downwardly inside the box in close relation to the walls thereof.

The developing solution is carried in an open topped, rectangular tank I8 positioned within the box I0. The bottom of the tank is received in a receiving band I9 secured to the bottom of the box I0 so that it'will always be placed in the same relative position in the box.

When the device is used for out films, pack films, or plates, a series of film holders 20 are used. Each of the film holders is suspended from a horizontal cross bar 2I so that they will depend within the solution in the tank I8. The cross bars 2| are carried in notches 22 in a rectangular rack 23. The rack 23 is secured to the extremities of a handle plate 24 which in turn is supported on a post 25 extending downwardly into the tank I8 to a foot plate 26 which rests upon the bottom of the tank. The film holders 20 are narrower than the width of the rack 23 so that they may be moved horizontally in this rack.

A surge plate 21 is hung over each of the end walls of the tank I8 opposite the edges of the film holders 20. The surge plates have downwardly turned upper edges 28 which over-hang the walls of the tank I8 and extending downwardly therealong. The angle between the downwardly turned edge 28 and the surge plate is such that, when the former is pressed inwardly against the sides of the tank, the lower extremity of the plate will swing inwardly into contact with the film holders 2Q. The cross bars 2| ride upon the rounded fold in the upper extr'emities of the surge plates.

The surge plates are alternately swung inward by means of an electric windshield wiper motor 2e. Such a motor is obtainable on the market and is ordinarily used for reciprocating the windshield wiper on an automobile, the wiper being suspended from an oscillating shaft 33 extending from the motor. In this case, the oscillating shaft 35! is provided with a crank memher 3! from which a crank pin 32 projects, A

crank block 33 is slidably mounted on the pin 32 and supports a yoke bar 34. The extremities of the yoke bar 34 are first bent rearwardly and downwardly thence forwardly to form looped extremities 35 which ride against the inner wall of the box Id. The free extremities of the yoke bar extend along each end of the tank [8 in spaced relation thereto and each extremity is provided with a threaded contact screw 36, the extremities of which are positioned to contact the down ,wardly turned edges 28 of the surge plates.

lltcanbe readily seen that if the crank member .31 is oscillated backland forth, it will oscillate the yoke member 34 back and forth in a horizontal plane. The yoke member is guided in the horizontal plane by means of supporting pins 3'? positioned. therebeneath. As the yoke member '34 oscillates back and forth, the contact screws 3'5 contact the downwardly turned edges 28 of the surge plates, alternately swinging the edges inwardly. -This creates an oscillating surging of the solution between the suspended plates. It also causes the film holders 20 to be pushed back and forth inthe solution so that both the solution and the holders are kept in motion. The

magnitude of this motion can be regulated by adjustingthe screws 36.

In the drawings, only one film holder has been illustrated. The rack illustrated, however, is designed to hold twelve film holders simultaneously suspended in the solution. The surge plates contact the entire twelve and reciprocate them simultaneously. The surge plates are provided with openings 38 through which the solution flows as the plates approach the walls of the tank. The openings lessen the resistance of the surge plates inmoving toward the end wall and prevent the solution from being forcedover the wall of the tank. t

The motor 29isattached to a motor plate 39 which is clamped to the wall of the box by means of a clamp screwAU. The clamp screw and the motor shaft drop into a notch 4| in the wall of the box, A projectionliS on the motor plate conp,

'tacts the bottom of the notch and supports the motor. The plate 39 closes the notch 4! to prevent the entrance of light to the box.

. It is desired to call attention to the ease with which thevarious parts may be removed for 33.'can be slipped from the crank pin 32. Therefore the entire device can be quickly assembled or disassembled without the use of tools.

For use with roll films the entire rack structure, previously described, is lifted from the tank and a roll bracket t3, shown in Fig. 3, is substituted. The roll bracket has a downwardly turned upper flap 44 which is hooked over either one of the surge plates 21 to support the rack in the tank. The lower portion of the rack is projected forwardly to form a shelf GB for supporting a reel post as, upon which any of the commercial film reels can be placed, such as indicated in broken line at il. The reel is supported on a cross bar 18 extending across the post 46. This submerges the entire reel below the surface of the solution and, at each movement of the surge plate, the entire reel swings beneath the solution so that, in this case also, both the solution and the negative are in motion.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims,

without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

l. A negative developing device comprising: a substantially rectangular tank; a surge plate; a downwardly folded upper edge on said plate overhanging the upper edge of said tank to hingedly supportsaid plate therein; and means for intermittently contacting the downwardly folded edge to swing said plate in said tank.

2. A negative developing'device comprising: a substantially rectangular tank; a surge plate placed at each end wall of said tank; a downwardly folded upper edge on each of said plates, said edges overhanging the top of said tank to hingedly support said plates therein; a reciprocating yoke member partially surrounding said tank at a point to contact said overhanging edges; and means for reciprocating said yoke member to alternately contact said edges to alternately swing said surge plates.

3. A negative developing device comprising: a substantially rectangular tank; a surge plate placed at each end wall of said tank; a downwardly folded upper edge on each of said plates, said edges overhanging the top of said tank to hingedly support said plates therein; a reciprocating yoke member partially surrounding said tank at a point to contact said overhanging edges; means for reciprocating said yoke member to alternately contact said edges to alternately swing said surge plates; and means for movably supporting a photographic negative between said plates so that the movements thereof will be communicated to said negative.

l. A negative developing device comprising: a substantially rectangular tank; a surge plate placed at each end wall of said tank; a downwardly folded upper edge on each of said plates, said edges overhanging the top of said tank to hingedly support said plates therein; a reciprocating yoke member partially surrounding said tank at a point to contact said overhanging edges; means for reciprocating said yoke member to alternately contact said edges to alternately swing said surge plates; a series of negative holders; and means for slidably supporting said holders between said plates so that they will be contacted by the latter and reciprocated within said tank.

5. A negative developing device comprising: a substantially rectangular tank; a surge plate placed at each end wall of said tank; a downwardly folded upper edge on each of said plates, said edges overhanging the top of said tank to hingedly support said plates therein; a reciprocating yoke member partially surrounding said tank at a point to contact said overhanging edges; a motor; a crank member actuated by said motor; and means connecting said crank member to said yoke to reciprocate the latter into alternate contact with the edges of said surge plates to swing the latter within said tank.

6. A negative developing device comprising: a substantially rectangular tank; a surge plate placed at each end wall of said tank; a downwardly folded upper edge on each of said plates, said edges overhanging the top of said tank to hingedly support said plates therein; a reciprocating yoke member partially surrounding said tank at a point to contact said overhanging edges; means for reciprocating said yoke memher to alternately contact said edges to alternately swing said surge plates; and adjustable means on said yoke for regulating the arc of contact with said edges.

7. A negative developer comprising: a housing; a light proof lid for said housing; means for clamping said lid in place; a developer tank; means for receiving said tank within said housing; means for suspending negatives within said tank; hingedly suspended surge plates in said tank; a motor mounted on the exterior of said tank; and power transmission means between said motor and said plates for swinging the latter within said tank.

8. In a negative developing tank, means for supporting negatives therein comprising: a rectangular negative rack having receiving slots in its opposite upper edges; a cross member in said rack; a post extending downward from said cross member into said tank; a foot plate supporting said post perpendicularly; a series of negative holders; and a horizontal top member on each holder extending beyond the side edges thereof and resting in said receiving slots.

9. In a negative developing tank, means for supporting negatives therein comprising: :1 rectangular negative rack having receiving slots in its opposite upper edges; a cross member in said rack; a post extending downward from said cross member into said tank; a foot plate supporting said post perpendicularly; a series of negative holders; a horizontal top member on each holder extending beyond the side edges thereof and resting in said receiving slots; and means for reciprocating said top members in said racks.

10. A light proof box for a photographic developing tank comprising: an open-topped box for receiving said tank; a downwardly flanged lid for said box supported on the upper edge thereof; a downwardly flanged inner lid secured on the lower face of the first lid and extending snugly into said box; a gasket between said first lid and said box; hooked ears extending upwardly from said box above the first lid; and a cross bar pivoted on the top of said first lid of a length sufiicient to swing into said hooked ears.

CHARLES MACE. 

